Humans' arrival time gets another look / North America inhabited earlier, some say

Rob Stein, Washington Post

Published 4:00 am, Thursday, November 18, 2004

2004-11-18 04:00:00 PDT Washington -- Archaeologists claimed Wednesday they had found evidence that humans lived in North America at least 50,000 years ago, far earlier than has been thought.

The claim was immediately met with skepticism by other scientists because the evidence had not gone through the usual process of review by independent researchers, which is especially crucial for something that would so dramatically rewrite human history. If humans migrated to the Western Hemisphere that early, it would force scientists to fundamentally rethink the early migration patterns of the species and the role of Homo sapiens so far back in this hemisphere.

But the researcher who led the team that made the discovery said he was confident the findings would hold up under scrutiny.

"It's really shocking -- we know that. Most archaeologists probably will reject this. We know we have our work cut out for us, to say the least," said Albert Goodyear, an archaeologist at the University of South Carolina. "But I believe it, so I have to call it as I see it."

The claim comes from pieces of charcoal and shards of stone Goodyear and his colleagues unearthed at the Topper archaeological site located along the Savannah River in Allendale County, S.C.

Modern humans are believed to have evolved in Africa between 60,000 and 80,000 years ago. Archaeologists have found evidence modern Homo sapiens migrated to Australia and central Asia about 50,000 years ago, and to Europe perhaps 10,000 years later.

But modern humans are believed to have migrated to the Western Hemisphere much later. For decades, the earliest signs of modern humans in the Western Hemisphere were believed to date back about only 13,000 years to a primitive culture known as Clovis, whose distinctive fluted projectile points have been found across the United States. Archaeologists have, however, begun to challenge the idea that the Clovis were the earliest human inhabitants in the area, citing findings that might push back that date to about 20,000 years ago.

But no one has previously claimed to have found any evidence that would push the date back 50,000 years.

In the new findings, Goodyear said his team dug down deeper than ever before at the Topper site and found tiny shards of flint that Goodyear believes are clearly the remains of ancient toolmaking. Then, the researchers found pieces of charcoal nearby in what could have been an ancient hearth, and sent the samples to UC Irvine for radiocarbon dating, which is considered the gold standard for determining the age of archaeological artifacts.

The results, released Wednesday, concluded the charcoal is at least 50, 000 years old.

The researchers plan to submit the findings to a scientific journal for publication but decided to release the results before that because of intense media interest, Goodyear said.

Other scientists said they respected Goodyear's work but found it difficult to evaluate the findings without seeing details.